| Steve Glendinning | 9df7305 | 2010-08-14 21:08:54 +0200 | [diff] [blame] | 1 | Kernel driver emc2103 |
| 2 | ====================== |
| 3 | |
| 4 | Supported chips: |
| 5 | * SMSC EMC2103 |
| 6 | Addresses scanned: I2C 0x2e |
| 7 | Prefix: 'emc2103' |
| 8 | Datasheet: Not public |
| 9 | |
| 10 | Authors: |
| 11 | Steve Glendinning <steve.glendinning@smsc.com> |
| 12 | |
| 13 | Description |
| 14 | ----------- |
| 15 | |
| 16 | The Standard Microsystems Corporation (SMSC) EMC2103 chips |
| 17 | contain up to 4 temperature sensors and a single fan controller. |
| 18 | |
| 19 | Fan rotation speeds are reported in RPM (rotations per minute). An alarm is |
| 20 | triggered if the rotation speed has dropped below a programmable limit. Fan |
| 21 | readings can be divided by a programmable divider (1, 2, 4 or 8) to give |
| 22 | the readings more range or accuracy. Not all RPM values can accurately be |
| 23 | represented, so some rounding is done. With a divider of 1, the lowest |
| 24 | representable value is 480 RPM. |
| 25 | |
| 26 | This driver supports RPM based control, to use this a fan target |
| 27 | should be written to fan1_target and pwm1_enable should be set to 3. |
| 28 | |
| 29 | The 2103-2 and 2103-4 variants have a third temperature sensor, which can |
| 30 | be connected to two anti-parallel diodes. These values can be read |
| 31 | as temp3 and temp4. If only one diode is attached to this channel, temp4 |
| 32 | will show as "fault". The module parameter "apd=0" can be used to suppress |
| 33 | this 4th channel when anti-parallel diodes are not fitted. |